As it is well known, the standardization activity in the Internet world is quite peculiar and is carried out by the Internet Engineering Task Force (IETF) which is a large open international community of network designers, operators, vendors, and researchers.
The standardization activity of the IETF always involves and involved single operations of the processing of data packets and no attempt has ever been made to standardize a whole functional model for a telecommunication equipment.
There is an enormous number of possibilities to combine and implement the various operations; how and when the various operations are carried out highly affect the overall functionality of an equipment and its effectiveness.